Paitc



L. A. JONES PLANE ILLUMINATOR Filed March 10. 1923 IN V EN TOR. d JOJZQS,

Patented Nov. 2, 1926.

1 lIINVF'IEZD STATES i 1,605,843 PATENT oFFICE.

LOYD JONES, F,ROCHESTER, NEW YORK, ASSIGIIOR T0 EASTMAN KODAK COM- PANY, OIF ROCHESTER, NEW YORK, CORPORATION OFYNEW YORK.

PLANE ILLUMINA'TOR. i

- application mea Maren A1c, 1923. serial No. 6424,23?.

' This invention relates to a plane illumilnator and more particularly to means for holdingand illuminating such materialas sheet music or lecture notes'.

`Li In rooms that aredarkened for the pro.

illuminate the entire surface to such an eXr* tent that notes at the 4least illuminated portions shall be easily legible. If, as is usual, the light is not well` distributed, this necessitates the illumination of' parts of the sheet far more than is necessary or desirable.' It is obvious that if the light raysare more.

evenly distributed over the whole' surface,

not only will the total amount of light used be smaller, but the amount of light necessary for the least illuminated portion is less,since the eye tends to accommodate itself to the 39 brightest light, and when the whole illumination is low and even the eye will be adi justed for much Yless light. y I The main objects of my invenconare to meet the requirements stated ab' e, and to make an apparatus that is simple in struc ture, inexpensive to manufacture and free from parts liable to' become 'out4 of order. These and other objects are attained by the apparatus hereinafter described and illustrated in the4 laccompanying Mdrawings, in which the same reference characters are used throughout to designate the same parts and in whichV 1 y Fig. lfis a perspective View of a music l stand embodying Lmy invention; i

rFig. 2 is a section on line II-TII of Fig. 1;

Fig. 3 isa plan of a mirror used in my apparatus; i j

Figs.' 4 and 5 are fragmentary .plans of other embodiments of the mirror.

tion comprises a sheet holder and illuminator 1 on a suitable support or post 2; It is in the form of an open tray having a bottom 3, on which thesheet 4 to be illuminated It is denear the bottom of the housing.

.of control by modifying the character of the The preferred embodiment of my inven-l may be placed, with side walls 5, a lower `ond wall 6 and an upper end wall or partition 7 The side walls 5 and bottom 3 extend beyond the partition 7 andare joined by a rear. ,wall 8 with a hinged door 9.. A top wall l() overhangs the partition 7 These and the walls behind the partition constitute a lamp housing within which is a socket 11 for alamp 12 which is preferably ot a long filament type positioned horizontally The wall or partition 7 has a -horizontally extended opening 13, the bottom 17 of which is above the lamp 12 so that no direct rays therefrom can reach the bottom surface 3 ofi the open tray. A' reflector 14 to be more`fully described later is mounted at an angle above the lamp and held at its lower edge by support 15. Its upper edge abuts arefiector 16 secured to that art of the top- 10 that overhangs. the wall If the partition 7 were absent and the bottom surface illuminateddirectly by the lamp with or without an ordinary specularly reflecting mirror, the illumination would fall off rapidly, being intense near the light and 'much less inthe far corners of the surface. l

While the shape and location of a specularly reecting mirrorV would aiect the distribution of light, there is at best with such an arrangement a contrast that is objectionable to the musician or lecturer, and, if the stand faces the audience, a glare that is annoying.

. The reflected rays are, however, capable reflecting surface. All specularly reiiected rays leave the surface at an anglev equal to the angle of incidence. Ifthe surface has perfectly diffuse reflecting properties, light falling upon it will be reflected equally in all directions. Every point becomes ja source of evenly distributed illumination. If, then, the rays that would be reflected to the more distant portions of the surface fall on` a specularly reflecting surface they will reach their destination as before; while if the rays that would be specularly reflected to the nearerand brighter portions fall instead 'on a di'usely reflecting surface, they will-be so distributed that part will reach the more distant portion increasing its illuminationv while only a part will reach the nearer portion so that its illumination will be less andV the surface as a whole will be more uniformly lighted. Such an expedient I apply to the reflecting means used in my improved illuminator.

If the partition were somewhat lower and the mirror 14 specularly reflecting, rays therefrom would be reflected upon the entire surface in the objectionable manner above described. The partition 7 is, however, at its ends, of the full height -of the housing but'is cut away at its center to..

furnish the horizontal aperture 13, the lower edge 17 of which is at such a height as to out off from the nearest portions of surface 3 all specularly reflected rays from the reliector 14. I furthermore render' portions of the reflector 14 matte, for instance, withA shown in this form there is a zig-Zag boundary line 2O between the portions, the part on'one side of the line being evenly matte.

Another method is shown in Fig. 4 where.

one marginal portion 21 is polished, and another portion 22 is very matte, the roughness Vbeino' lessened by degrees to an indis` tinguishable border between the -two portions. In Fig. 5 there is a wavy line of point of reflector 16 may be considered as a source of evenly distributed illumination. From any point such as D, light will -fall on the entire surface 3, a few rays being indicated. Of course, the portions nearer to the lamp house will be more brilliantly illuminated from this source. It is apparent that the distribution of light may be varied by changes in the position and form of each of the reflectors, the degreeof diffusion, the 'position and shape of the lainp filament, the height of edge 17 and other constants of the .instrument and that for a box of any pardemarcation 23 between the polished portion 24 and matte' portion 25, the degree of roughness of the latter also lessening toward that line.

Such a mirror is placed at 14 with the polished portion uppermost. The limits of specularly reflected rays are indicated by those falling at A and B, the first limit being imposed by the edge 17 and the second ,by the surface of reflector 16. The farther porti-ons of surface 3 receive rays from the polished portion 18 as Idoes the specularly reflective mirror 26 on the inner surface of wall 6, from'which rays are reflected back principally on the portions farthest from the lamp housing. rlhe points near A will receive but few specularly reflected rays from the mirror 14 and mirror 26, and those to the'left of A will receive only a few, if

- any, specularly reflected rays from 26." Theles diffusely reflected light from the-lower art of mirror 14 will also be largely cut o the wall 7 from the regionsv to Ilthe left of- A, though a few rays from the lesser diffuse portions will re'ach it. The diffusely -reilected rays will fall in part on the rear of partition 7 and be `lost and in large part on the region to the right of A.

The reflector 16 has a surface that is entirely diffusing. This reflector extends out to such a distance Oas to intercept allpos sible rays from the lamp through the aperture 13. The path of the limiting visible ray is indicated by a line from the eye E. Every ,ters Patent is:

from one portion ticular size and shape changes in proportions and dimensions of these optical elements will be necessary. I have pointed out, however, the sources of light falling on thedifferent portions of the surface to be illuminated; and the modification of these to suit particular dimensions is a matterl of design. It is possible thus to 4control the illumination in such a way that it is remarkably even over the whole surface.

'It is to be understood that the above structure is to be Aconsidered as an example of my invention and that I consideras within the scope thereof, all such modificationsand equivalents as fall within the appended claims.

' Having thus described my invention, what I claim as new and desire to secure by '1. An illuminator comprising a supportwith va surface open'for inspection, alamp for illuminating said surface and a reflector along one edge of the support for directing Letrays from the lamp to the open surfacegof the support, a portion of the reflector having high specularly reflecting properties and directing specularly reflected light principally to the portions of the surface lfarthest therefrom', and another portion of the reflector having high diffusely reflecting properties.

2 A11 .illuminator comprising a surface to be illuminated, a housing at one sidee of said surface, alamp within the housing and a reflector for directing rays from the lamp to the surface, one portion of-fthe reflector having high di-flusely reflecting properties, and another portion having highaspecularlyreflecting properties, the reflecting properties of the reflector changing gradually to theother, the second portion being positioned to reflect light principally upon the portions of the surface farthest from the light..l

3. An illuminator comprising a surface to be illuminated, 'a housingl at one side of the surface and including a partition, a socket for a lamp within the housing and sepathat no direct rays from a lamp in the socket can fall on the surface, said housing hav-.

ing a top overhanging the partition by a slight distance only, ing and under said 'lective.

4. An illuminator -com be illuminated, a hfllx surface and includ portion to the other the portion being position principally upon the po farthest from the housi g 6. An illuminator com a bottom and with Wa housing Aincluding one overhangingsaid Wall, ousing and behind means for directing l lamp to the bottom ments being so arran from the lam either g4 or are visiblev rom anypoint outside of the llluminator.

7. An illuminator co a bottom and with walls at itsl edges, a vhousing including gne of saidl walls and overhanging said wall, a lamp within the housing and behind said Wall, reflecting means for directing jfrom said lamp to the bottom o the elements being arranged so that no dione of the other side walls. rect rays from said lamp \either fall on 14. An

and means in the houstop for rellec from a lamp in the socket to the l portion of said means being dillusely relective and a portion being specularly reting rays surface, a

prising a surface too sing at one side of the g a partition, a socket for a lamp Within the housing and separated .by the partition `from the surface sov that the bottom of the tr no direct rays from a lamp in the socket can fall on the surface and means for refleeting rays from a lamp in they socket to the surface, a portion of s specularly reflective and dii particularly to the portions) farther from the housing, an said means being ditlusely r \5\ An illuminator comprising a surfaceto be illuminated, a housing at `surface and includin g light rays of tllebsurface d a portion of one side of the g a partition, a'socket for a lamp within the housing and separated by the partition from the `'surface 'so that no direct rays from can fall on the surfa fleeting rays from a lamp in the socket to the surface, a portion of said me diffusely reflectwe and a p ularly reflective, the rele the vreflector changing in the socket means for reans being ortion being specctive properties of gradually from one specularly reflective ed to reflect light rtions of the surface prising a tra .with lls at its e ges, a of said walls and a lamp within the said wall, relectin ilection. ight rays from said of the tray, the. eleged that no direct rays fall on the bottom mprising a tray with Walls at its edges, a housing includin one of said walls and overhangin sai wall, a lamp within the housing an behind said wall, specularly rey fleeting means for directing light rays from l said lamp to they bottom ofthe tray, the elements being so arranged that no directF or specularly reflected rays are visible from any point outside of the illuminator.

8. An illuminator comprising a tray with specularly light rays Y 'Leonesa i housin overh means and housi said lamp, Where ing from said l aid means being fall upon one of said element 10. An illuminator com with a bottom an housing includin f` overhanging sai housing and reflectil'lg means for lamp only upon the bo upon the interi the Walls, tirely sur ray of 1i any direction ments. 11. A plane illumina't open tray With a plane b nated a h lamp Wit housing and havi a reflect amp in any hin the housin separating the lamp from th ng an opening above the lam or inthe housin fleet rays from the la ing upon the plane, being capable of hig portions' vbeing capa 12. An illuminator com `tray with a bottom surface .a housing at one side of th 'ing a partition, a lam and separated face so that can` fall on the surf positioned above t to reflect rays from th a portion of the reii reflective and directi larly to the portions from the housin tor ,being dilfuse 13. An illumi tray ylwith side luminated, said walls, and adapte a lamp house i a reflector i d to direct li tray', a portion of said r dilfusely 'reflectin having high spe ray, ties, and a reflector on visible from any point tor and so that no specuarer visible from vany omprising a tray With at its edges, a said walls and amp within the aid wall,y reflecting a'ys from said lamp to ay, lthe walls reflecting ng entirely surrounding by array of light proceeddirection will prising a tray 11s at its edges, a gone vof 'said walls and d Wall, a lamp within the d said wall,`s

ecting rays rom said ttom of the or of the Walls kand relecting means and-,ho rounding saidi ght proceeding f ecularly tray and housing, using en'- lamp, whereby a rom said lamp in upon one of said eleor comprising an ottoxn to be illumiside of tle tray, a g, one wallpo-f the prising an open to be illuminated,d e tray and includp in the housing 'partition from the\suf d` ect rays from the lamp a reflector angularly artition and adapted e lamp to the surface, ector being specularly ng light rays particuof the surface farther and the rest of the rellecy rellective-.

omprlsm an o n walls and a botton to bepialncluding one of n said lamp house ght rays across said eilector having high g properties and a portion y reflecting proper# er surface of e tray p, 'and g in a position to remp through the openportions of the reflector h specular reflection and ble of `highly diffuse re- .illuminator comprising an open 13 I tray with side walls and a bottom to be ilties, the side Wall opposite the lamp house.

luminated, a. lamp house including one of having its inner surface with high specu saidlwalls, a reflector in said lamp house larly reecting properties.

and adapted to direct light rays across said Signed at Rochester,-New York, this 7th 5 tray, a portion of said refiector having high day of March 1923. diusely reecting properties and a portion l having high specularly reflecting properl LOYD A. JONES. 

